Official Electric Fan wiring thread!

[eurosport22]

bump with boostineuros. i cant find one place that has them in stock

[BoostinEuros]

Are there any alternatives to the temp switch you linked? They seem to be out of stock everywhere I check (Pelican, RMeuropean)

[328ijunkie]

If you're running no clutch fan you have to get a Lower temp switch like a 88-98 as the stock one is designed around a clutch fan being thete

[SHunter]

Well, that makes sense. These cars definitely have a weakness in the cooling system and I guess the 80C can buy you some time when things go haywire.

I'm still gonna stick with the factory setup for now since my entire cooling system is new, I don't have AC, and I live in a pretty cool environment. Hoping that big 'ol fan I just bought keeps the temps rock steady.

-Steven

[328ijunkie]

Well ill chime in about this since i made the thread i guess.

Not 100% sure about OBD1 but the OBD2 ECU triggers closed loop at 165F. So using an 80C thermo is plenty fine. The ECU also Knows exactly what temp its at so it adjusts fuel trims and stuff accordingly. Yes it is always better to run an engine as hot as possible to get the most efficiency/power out of it, thus why BMW now uses 99+C thermo's in newer cars. But the biggest problem with that is no buffer when a failure occurs. Thus you have all these M52TUs/M54s and up pulling head bolt threads and stuff like that because the second they do start to run hotter than designed its already too late, in addition to the fatigue it puts on the aluminum running it that hot all the time and heat cycling it at those temps.

The biggest problem is how prone to issues these cooling systems are. Fan clutches failing, Hoses failing, WPs failing, etc and if running the factory setup you have no buffer to keep the motor from exploding if you do have an issue. Yes you would get marginally better MPG/power running it hotter but i prefer to keep it safer and prolong the life of the motor.

[SHunter]

What's the point of running the engine so cool? All the fuel and timing maps are based on a 92C engine not an 80C engine. In OBD2 an 80C thermo should cause a CEL and keep the engine in open loop all the time, killing gas mileage and losing power over most of the rpm range. Am I totally wrong here? For OBD1 you might not get a CEL but it won't run as well. It seems like you'd only want to do this on a track car that is only run at WOT all the time.

A simpler solution to all this would just be to run the factory switch, thermo, resistor, wiring, etc and not worry about changing around the whole system. Is there a big benefit to doing this that I'm not seeing?

-Steven

[gkurey]

I will investigate and let you all know, thanks for the input!

[748Snowman]

+1 for sticky

[328ijunkie]

On all my 82 single pole sensor cars it comes on a tick over half.

[Highway1]

It should come on just before the halfway mark

Does your Spal fan have two speeds built in? Most after market fans do not. It sounds like you have the high speed (88°) wire hooked up to the fan. Try switching to the other wire.

[gkurey]

I run the 80/88 3 pole sensor, and the fan kicks on low speed at about 2/3 up the gauge...seems a little off? I run the 80C T-stat and my temp while driving holds between 1/3 and 1/2 marks. If I sit in traffic, the temp creeps up above half and, as stated above, the fan doesn't start up until the upper 2/3 area. Is that what you guys with the 80/88 Are experiencing?

Seems wrong to me....maybe they accidentally gave me a 91/99 switch? Can anyone vouch for the approximate temp at the 2/3 mark? My fan is an aftermarket SPAL and the wiring is good to go, just not working in the expected regime.

[328ijunkie]

Glad you got it figured out :d

[Highway1]

Nope. Only when snowflake is on, which is useless to me. I'm going to try a working diode and see what happens.

Edit: I thought I checked all my fuses... and I had checked all the fuses. The problem was one was missing. doh!

[328ijunkie]

Does the relay fire?

[Highway1]

I bypassed the diode and now the low speed comes on when i press snowflake when i jump blk to blk/brown it activates high speed. however when snowflake is NOT on, jumping the three prong plug does nothing.... i'm confused.. is it safe to run without the diode or is that why jumping the plug doesn't work?